Telephone-receiver.



PATENTED AEE. 18, 19o-5.

C. T. MASON.' TELEPHONE EECEIVEE.

APPLICATION FILED FEB. 2'1. 1905.

A 7 /VVE/VYUR UNITED STATES Patented April 18, 1905.

PATENT OFFICE.

CHARLEST. MASON, OF SUMTER, SOUTH CAROLINA, ASSIGNOR TO SUM- TER TELEPHONE MANUFACTURING COMPANY, OF SUMTER, SOUTH CAROLINA.

TELEPHONE-RECEIVER.

SPECIFICATION forming part of Letters Patent No. 787,583, dated April 18, 1905.

Application led February 27, 1905. Serial No. 247,457.

T0 (1J/Z whom, it may concern:

Be it known that I, CHARLES T. MASON, a citizen of the United States, residing at Sumter, in the county of Sumter and State of South Carolina, have invented new and useful Improvements in Telephone-Receivers, `of which the following is a specification.

This invention relates to telephone receivers, and has `for its object to provide improved means for holding the parts of the structure together. It includes improvements in the casing and also improvements in the parts supporting the magnet structure. In structures of this kind it is desirable that convenient and secure means be provided for assembling the various parts and for supporting the magnet structure in the casing. In receivers wherein the magnet structure is held by the cap or earpiece alone any loosening thereof results in disturbance of the adjustmentvhich is objectionable.

My invention provides means for securely clamping the magnet structure and for locking the earpiece so that it cannot be readily loosened.

In the accompanying drawings, Figure l is a central longitudinal section of the receiver. Fig. 2 is a rear end view of the casing with the cap at the rear removed, showing particularly the corrugations which lock the earpiece to the shell of the casing. Fig. 3 is a detail in section, showing the manner of fastening the pole-pieces to the magnet. Fig. 4 is a detail in perspective of one of the coils.

Referring specifically to the drawings, A indicates the cap or earpiece, which screws onto the metal cup B and clamps the diaphragm a therebetween. Beyond the screwthreads the rim of the cap is extended and waved or corrugated, as at p. The rim of the iront end of the sleeve or shell F has similar waves or corrugations which tit in the corrugations in the cap when the parts are assembled, and consequently lock the sleeve and cap together, so that the latter cannot be unscrewed until the sleeve shall have been withdrawn suiciently to disengage the corrugations.

The sleeve F of the casing is held in place by the removable cap G at the rear end,which screws on a threaded block 0, clamped by a bolt e between the rear ends of the magnetbars g. l The front end of the sleeve F abuts against a vshoulder j' on the cup and is held in place by the cap G when it is screwed on the block 0.

In assembling the parts the cap is rst screwed on the cup. The sleeve F is then placed over the magnet, with its front end abutting against the shoulder j and its corrugated rim tting in the corrugations in the rim of the cap A. The rear cap G is then screwed on the block and vholds all the parts assembled together.

The magnet structure comprises the bars g, clamped at their rear ends upon the iron block 0, and the pole-pieces a, which are forced through slots in the bottom of the cup B and secured by rivets q to a brass block m., the whole being held together by a bolt c, which also holds in place the ber piece f between the magnet-bars, through which liber piece the terminals of the receiver-cord H extends.

The coils b are mounted upon the ends of the pole-pieces within the cup and are removably held in place by screws (l, which extend through ears on the inner or rear end plates of the coils'and into taps in the bottom ot' the cup.

It will be seen that the ear-cap and diaphragm cannot be loosened while the sleeve F is in place. The sleeve must first be disengaged by removing the end piece G. This prevents disarrangement due to unauthorized tampering with the earpiece, such as attempts to unscrew the same, and also provides convenient means for assembling and holding the partsof the receiver together. f

The pole-pieces a have at their side edges shoulders a', which rest upon the bottom of the cup, as shown in Fig. 3, and when said pole-pieces are forced through the slots in the bottom of the cup and drawn up to the block m by the rivets q the pole-pieces and cup are rigidly secured together in exact axial alinement, and in the event of its being necessary to rear end of the sleeve.

2. In a telephone-receiver, in combination, a shell, a magnet structure therein having a cup fixed to its front end with its rim against the front end of the shell, a threaded block iixed to the rear end of the structure, and a cap screwed on the block and against the rear end of the shell.

3. In a telephone-receiver, in combination, a'shell, a magnet structure therein having a projecting cup forming an abutment for the front end of the shell, a block fixed to the rear end of the magnet and having a projecting threaded portion, and a cap screwed on the threaded portion, and against the end of the shell.

4. In a telephone-receiver, the combination with a magnet having a cup upon the front end thereof, of pole-pieces secured to the magnet and extending through the bottom of the cup and having shoulders resting thereon, coils on the pole-pieces in the cup, a cap over the cup, and a diaphragm clamped between the cap and cup.

5. A telephone-receiver casing, comprising a cap, and a shell, having interlocking projections preventing them from being turned with respect to each other, and means to bind the cap and shell together.

6. In a telephone-receiver, in combination, a cup, a magnet structure fixed thereto, a cap screwed on the cup and having a rim extending beyond the screw-threads, a SheILitting within said rim, the rim and shell having interlocking devices preventing relative turning of the parts, and aremovable cap secured to the magnet structure and bearing against the rear end of the shell.

7. In a telephone-receiver, the combination with a cup in the casing, of pole-pieces fitting through slots in t-he bottom of the cup and having shoulders resting upon said bottom, a block xed under the bottom of the cup, between the pole-pieces, whereby the pole-pieces and cup are rigidly secured together, and a magnet connected to the pole-pieces.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

CHARLES T. MASON .Witnessesz MURR HALL, C. G. RowLAND. 

